1. Field of the Invention
The present invention is directed to a device for terminating flow of a liquid, and particularly to a device which terminates the flow after continuous (i.e., uninterrupted) flow of a predetermined duration.
The device is useful in any application in which it is desired to limit the continuous (i.e., uninterrupted) flow of a liquid to a predetermined length of time, e.g., 20 minutes. The device is particularly useful when connected in series with the outside water supply of a residence, office or factory building for preventing water damage from broken pipes, and can also be used to prevent flooding in a water vessel such as a boat, house boat or yacht.
2. Description of the Background Art
Many conventional devices monitor and/or control the flow of fluids.
U.S. Pat. No. 5,050,772 issued on Sep. 24, 1991 to Brane et al. and discloses a device which is connected in series with an ordinary household filter to stop the flow of water after a period of time corresponding to the life of the filter. The device has a turbine, gears and a valve to limit the flow of water according to the reduction ratio of the gears and the rate of the incoming water flow.
In the device disclosed in the '772 patent, when the water is turned on and then off, as in normal use, the device does not reset itself. The purpose of the device is to measure the cumulative flow of the water, thus the device does not reset itself until the predetermined period of time has elapsed. The predetermined period of time may be many hours to allow for the filter to become expired. If the time period is made shorter, e.g., 20 minutes, the device must be reset by hand at each 20 minute interval, and the device is not able to reset itself when the flow of water is for less time than the predetermined time period. In other words, the device measures cumulative flow regardless of the duration of any given period or duration of continuous (i.e., uninterrupted) flow.
U.S. Pat. No. 3,807,452 issued to Buckman on Apr. 30, 1974 and discloses an automatic fluid timer device which uses mechanical and hydraulic means. The device employs a diaphragm-actuated shaft which causes a valve to be raised or lowered off or on its seat and the flow direction control valve to open and close the appropriate ports. This device is structurally complex and thus is expensive to manufacture and assemble.
U.S. Pat. No. 4,522,221 issued to Chivens et al. on Jun. 11, 1985 and discloses a timed flow control valve for regulating fluid flow from a valve input to primary and secondary fluid flow outlets.
A timer/control is used to select between the primary and the secondary fluid flow outlets, and a solenoid and springs are used in combination to open and close the valves. This device is also structurally complex. Further, this device employs electrical circuitry.
Many conventional devices employ a turbine and gearing to distribute a liquid (e.g., water) through a plurality of ports in a rotary valve.
U.S. Pat. No. 4,461,319 issued on Jul. 24, 1984 to Macosko and discloses a water modulator which has a turbine, gears and a rotary valve for varying the flow rate in accordance with the cyclical periodic operation of the rotary valve.
The water modulator disclosed in the '319 patent does not act to terminate the flow of liquid after a predetermined duration, and the device is not able to reset itself if the continuous (i.e., uninterrupted) flow is shorter or longer than the predetermined duration. Rather, in Macosko's device, the turbine and gearing impart rotational movement on the rotary valve to produce the cyclical periodic water flow.
U.S. Pat. No. 4,817,656 issued Apr. 4, 1989 to Gould and discloses a fluid distribution apparatus with an impeller-driven gear reduction mechanism and more than one outlet valve controlled in response to the gear reduction mechanism. This device suffers from the same deficiencies noted above with respect to the modulator disclosed in the Macosko '319 patent, i.e., the device does not terminate flow of a liquid after a continuous (i.e., non-interrupted) flow of a predetermined duration, nor can the device reset itself after flow of a predetermined duration.
Various other references disclose devices which include gears for alternately directing fluid through a plurality of outlet ports and/or which include electrical means for controlling the flow rate of a liquid. Nonetheless, there are presently no simple mechanical devices which are able to terminate flow of a liquid after the liquid flows continuously for a predetermined duration.